ok so this is going to be long but this is a review of my trip to west yellowstone for testing the TKS SPX proto #3. First of all overall I was very impressed with the bike, it made it 3 of 4 days of riding with very few issues, one day I took of for some R&D work at a buddies shop.
In 4feet of deep soft snow with a layer of hard crust in the middle the bike was about a 5/10, it reaaaaalllllly trenched hard, I could only go in 2nd gear and not for long with out tracks to catch keep me going, it was like riding a 121 out west. My buddy had yz250 with a 136 timbersled inspired kit would literally do circles around me. also I made my ride height to high, so I kept tipping over every time I had to put my foot down when I stopped, my foot just anted to keep going down I did ok on the flats and down hills were a blast but other than that I was working really hard! My gearing is a 13 to a 16 to a 19, which seemed perfect for MN but at elevation was to high and I was wishing I had more power. The suspension worked great, it was very smooth and the motocross shock in the back really soaked up the rough washboard trails to the back country. even the guys on the sleds didnt want to try to keep up with me!
I have a pretty good idea on how to fix the trenching issue so we will be working on that this week, along with a new subframe design that has not been done in snowbikes yet!
My kit has the SLP powderpro, I can say that it was very stable on the groomed trail, sunday we put on 72 MILES of ALL TRAIL RIDING. I was able to easily top the bike out at 57 mph and feel in control and even ride one handed! (I had to wave at my buddy on his 03 rmk 800 as he got towed back .) I averaged 40mph on the trail, the rougher the trail got the better the ski stuck. however the ski stock pushed reaaaallly bad at first, after I put a set of trackers on the sides it was much better, but, not perfect. in the morning on the really hard iced trail the ski held very well with no pushing in the corners, but would dart from catching other ski ruts. in the afternoon, when the trails loosened up the ski went very straight and did not dart, but it would push/wash out, if you turned the ski too much in the corners. the most fun was hitting the rough burmed up corners, it would stick super hard and you could just pound the corners! but some of the tighter flat corners (switch backs) if I wasnt careful it would start to wash and I would have to put a foot down
in the pow I compared it to my buddies bike with a simmons and I could not lean it as far as the bike with the simmons before it would wash.
on snow that had tracks but not groomed trail, like where you and all your 2 ski buddies turned around to go back up the hill, it would wash all most every time i tried to turn,at any speed, even after I put the trackers on, but they did help.
I am not sure if all the handling issues were based solely on the ski, i wonder if has to do with the rubber bushing I used for the spindle. if anyone has ideas on that it would helpful.
I am sure that a center keel ski is the way to go for snowbikes, I am not sure what one it would be, it may be the curve ski, but dont disregard the ski because it is not the norm.
oh another thing compared to a dual keel ski road crossings are much more controlled, smoother and much safer, I have yet to feel scared when crossing a road, I could never say that for other bikes I have rode, when crossing roads on the dual keel ski I always felt like I had to be tipped slightly to one side so I was on one carbide, I dumped the bike on the tar three separate times! so far with the slp I have never.
